The invention relates to a method of exchanging a printing unit at a running rotary printing press, wherein at least one first printing unit is withdrawn from a printing medium and a second printing unit for printing the same image with the same register is set against the printing medium.
When certain kinds of printing media, such as fleece for baby diapers, are printed on a rotary printing press such as a flexographic printing press, the printing cylinders employed therein have only a short lifetime, because the printing plates are soiled relatively quickly by, e.g., dust particles that are released from the printing medium. For this reason, frequent interruptions of the operation for cleaning the printing plates on the printing cylinders are necessary. This causes a reduction of the productivity and, consequently, increased costs.